JP2000143661A - Reduction of residual organic solvent in tris-(2,3- epoxypropyl)-isocyanurate crystalline substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To industrially advantageously reduce a residual organic solvent in a crystalline substance by crushing the granules of the subject crystalline substance and removing the solvent from its surface under evaporation of a volatile component. SOLUTION: A residual organic solvent in a crystalline substance is reduced by crushing (A) tris-(2,3-epoxypropyl)-isocyanurate crystal granules and removing the solvent in the surface of the granules under evaporation of a volatile component (preferably crushing in an air stream). Preferably, the component A is crushed to 0.5-20 μm average particle diameter. A concentration of the residual organic solvent can be made to <=300 ppm by the crushing. Preferably, the component A is a β-type crystal particle and is obtained by subjecting an ester obtained by reacting cyanuric acid with epichlorohydrin in the presence of a catalyst to dehydrochloric acid with an alkali, separating the resultant alkali metal chloride and crystallizing the resultant reacted solution. By the method, epichlorohydrin as a residual organic solvent can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to tris- (2,3-
(Epoxypropyl) -isocyanurate A method for reducing the residual organic solvent in a crystal by removing the solvent remaining in the crystal from the particle surface by evaporation of volatile components from the particle surface, particularly by mechanical pulverization in an air stream. It is.

[0002]

2. Description of the Related Art Solder resist inks using a photosensitive prepolymer and a thermosetting resin in combination with a recent demand for characteristics of a solder resist material such as adhesion, electric insulation, solder heat resistance, and solvent resistance have been increasing. The composition has been used. That is, after the solder resist pattern is formed by the photosensitive prepolymer, the above-mentioned required characteristics are to be satisfied by thermosetting. In addition, the demand for higher density of printed wiring boards with the recent reduction in the size and weight of electronic equipment, lower bleeding when forming solder resist patterns for surface mounting of components, and more precise embedding between circuits has been increasing. ing. Therefore, as a thermosetting resin used in combination with the solder resist ink, a fine solid epoxy having high solvent resistance is desired.

[0003] Tris- (2,3-epoxypropyl) -isocyanurate is an example of a solid epoxy satisfying the above-mentioned required properties. Tris- (2,3-epoxypropyl) -isocyanurate has three asymmetric carbons, and all three asymmetric carbons are aligned (2R, 2 ′).
R, 2 "R) -tris- (2,3-epoxypropyl)
Crystals that are equimolar mixtures of -isocyanurate and (2S, 2'S, 2 "S) -tris- (2,3-epoxypropyl) -isocyanurate are generally referred to as β-type crystals and have a temperature of about 150 ° C. It is known that a high melting point type crystal is provided, because the two types of enantiomers form a molecular lattice having a pair of strong six hydrogen bonds and form a crystal lattice. On the other hand, one of the three asymmetric carbons
(2R, 2R, 2S) -tris- (2,3-epoxypropyl) -isocyanurate and (2S, 2S, 2R) -tris- (2,3-epoxypropyl) -isocyanate having two different optical anisotropies Crystals composed of a mixture of nurate are generally referred to as α-type crystals and do not have the above-mentioned crystal structure, and thus give only a low melting point of about 100 ° C. The β-form tris- (2,3-epoxypropyl) -isocyanurate crystal has not only a high melting point but also a very low solubility in various solvents, so that it can be used as a cross-linking agent for heterogeneous compounds and reactive polymers. When used as a reactive mixture of a mold, the reaction during storage until forcibly cured does not proceed. Until now, it has been used for electric and electronic material applications, for example, a photo-curing / thermo-setting solder resist ink composition.

The liquid epoxy composition may be thickened during storage due to the dissolution of a part of the epoxy compound in a solvent, or may cause poor elution when washing away the unexposed portion due to sticking with the photosensitive prepolymer. . 7-177
No. 37, β-type tris- (2,3-epoxypropyl)
Using isocyanurate as the poorly soluble epoxy compound; Β-type tris- (2,3
The (epoxypropyl) -isocyanurate fine particles are in a state of being wrapped in the photosensitive prepolymer, and do not lower the solubility of the unexposed portion of the photosensitive prepolymer.
Further, since it is hardly soluble in an organic solvent, the exposed portion is hardly affected by the developing solution, and does not cause a decrease in sensitivity. Furthermore, the storage stability of the solder resist ink composition is excellent.

Conventionally, β-type tris- (2,3-epoxypropyl) -isocyanurate has been
(2,3-epoxypropyl) -isocyanurate and α
As a method for dividing and producing tris- (2,3-epoxypropyl) -isocyanurate, α-tris-
(2,3-Epoxypropyl) -isocyanurate dissolves relatively well and β-type tris- (2,3-epoxypropyl) -isocyanurate is difficult to dissolve, for example, a resolution method using an alcohol such as methanol. was there. For example, the Journal of Thermal Analysis (Journal of Thermal Analysis)
is) Vol. 36 (1990), p. 1819, the separation is carried out using a methanol solvent. Plus
Und Kautestuk (Plaste und Ka)
utschuk) 23 Jahrgang Heft4 /
In 1975, first, β-type tris- (2,3-epoxypropyl) -isocyanurate was separated using a methanol solvent, and then β-type tris- (2,3-epoxypropyl) -isocyanurate was purified with chloroform. ing. In addition, Vol. 3 (1990)
On page 169, tris- (2,3-epoxypropyl) -isocyanurate obtained by synthesis is put into methanol, heated and stirred, and undissolved components are filtered off. The obtained undissolved product is methyl ethyl ketone. Recrystallize and form β-tris
(2,3-Epoxypropyl) -isocyanurate crystals are obtained.

[0006] Most of the β-type tris- (2,3-epoxypropyl) -isocyanurate obtained by such a dividing method is difficult to grow crystals and has a small particle diameter, so that the filtering operation becomes extremely difficult in the filtration step. I do. Therefore, it is not preferable that crystals obtained by crystallization are too fine.

In one division operation of the above division method, β-type tris- (2,3-epoxypropyl)-
Since the crystallization solvent, chlorine-containing impurities and other impurities are easily included in the isocyanurate crystals, it is necessary to further remove the crystals by recrystallization or melting the crystals once.

In Japanese Patent Publication No. 48-24039, a chlorhydrin ester of isocyanuric acid obtained by reacting cyanuric acid with epichlorohydrin is subjected to dehydrochlorination with an alkali to separate an alkali metal chloride produced. The solution of (2,3-epoxypropyl) -isocyanurate in epichlorohydrin is concentrated to give tris- (2,3-
Epoxypropyl) -isocyanurate concentration 50-60
%, Cooled to 20 to 25 ° C., and tris- (2,3-epoxypropyl)-with a yield of 27% based on cyanuric acid.
Crystals of isocyanurate are obtained. However, since it is crystallized from an epichlorohydrin solution, there is a problem that epichlorohydrin and the like are contained in a large amount in the crystal. Furthermore, epichlorohydrin is not only harmful to the human body, but is also composed of hydrolyzable chlorine harmful to electronic materials, so that it is desirable to minimize the amount. In order to remove epichlorohydrin in the crystal, it was impossible to remove the residual epichlorohydrin unless the crystal was heated above its melting point and melted once. Such a method complicates the manufacturing process, increases the manufacturing cost, and is not industrial.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a tris-
(2,3-epoxypropyl) -isocyanurate crystals, especially β-form tris- (2,3-epoxypropyl)-
An object of the present invention is to provide a method for extremely reducing the residual amount of the organic solvent, particularly epichlorohydrin, of the isocyanurate crystal.

[0010]

SUMMARY OF THE INVENTION The present invention provides a tris-
Residual organic solvent in tris- (2,3-epoxypropyl) -isocyanurate crystal by grinding (2,3-epoxypropyl) -isocyanurate crystal particles while evaporating volatile components from the particle surface This is a method of reducing the amount of the light.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, pulverization in which volatile components evaporate from the particle surface includes pulverization performed in an air stream and pulverization performed under reduced pressure. In particular, pulverization performed in an air stream is effective.

The pulverization in the air stream is performed, for example, by a 200 AFG type counter jet mill manufactured by ALPINE, K Krimoto manufactured by Kurimoto.
This is performed using a pulverizer such as a J-200 type cross jet mill. This type of pulverizer is a mechanism in which high-pressure air or an inert gas (for example, nitrogen) is blown into a pulverizer together with a sample to collide and pulverize sample particles. The pressure of this gas is 1 to 10 kg / cm ² . With this gas flow rate, the volatile components evaporate from the surface of the particles newly generated by the pulverization, and the organic solvent contained in the crystals is reduced.
The process is performed until the crystal particles are pulverized to an average particle size of 0.5 to 20 μm. At this time, the concentration of the residual organic solvent in the pulverized crystalline particles is 300 ppm or less, usually 100 to 2 ppm.
Obtained at 00 ppm.

In the present invention, the tris- (2,3-epoxypropyl) -isocyanurate crystal particles may be any tris- (2,3-epoxypropyl) -isocyanurate crystal having an average particle diameter of 20 to 500 μm. In particular, β-type tris- (2,3-epoxypropyl) -isocyanurate crystal particles can be preferably used.

The β-form tris- (2,3-epoxypropyl) -isocyanurate crystal is, for example, a chlorohydrin ester of isocyanuric acid obtained by reacting cyanuric acid with epichlorohydrin in the presence of a catalyst, The alkali metal chloride produced by dehydrochlorination with an alkali is separated, and can be obtained by crystallization from the obtained reaction solution containing tris- (2,3-epoxypropyl) -isocyanurate.

In the method for crystallizing from the above reaction solution,
The residual organic solvent is epichlorohydrin.

Β-tris- (2,2) from the above reaction solution
3-epoxypropyl) -isocyanurate crystals
Steps (A), (B), (C), (D) and (E): Step (A): (a) 1 mol of cyanuric acid, (b) 5-180 mol of epichlorohydrin, and (c) as a catalyst Reacting 0.001 to 0.1 mol of at least one compound selected from the group consisting of tertiary amines, quaternary ammonium salts, quaternary ammonium bases, trisubstituted phosphines, and quaternary phosphonium salts 3 to 6 mol of an alkali metal hydroxide or an alkali metal alcoholate is added to the reaction solution obtained in the above, and after dehydrochlorination, the alkali metal salt is removed to give tris- (2,3-epoxypropyl) -isocyanurate. A step of obtaining a reaction solution containing the tris- (2,3-) obtained in the step (A);
A step of preparing a reaction solution containing (epoxypropyl) -isocyanurate to a solid content concentration of 10 to 50% by weight; step (C): the liquid obtained in step (B) is a saturated solution A step of adding a seed crystal at a temperature 5 to 20 ° C. lower than the temperature at which (C) is formed.
It can be produced from a step of obtaining crystals by slow cooling at a cooling rate of not more than hr to obtain crystals, and a step of washing the crystals obtained in step (E): step (D).

In the above method for producing the β-form tris- (2,3-epoxypropyl) -isocyanurate crystal, in the step (A), (a) 1 mol of cyanuric acid and (b)
5 to 180 mol of epichlorohydrin, and (c) at least one selected from the group consisting of a tertiary amine, a quaternary ammonium salt, a quaternary ammonium base, a trisubstituted phosphine, and a quaternary phosphonium salt as a catalyst. 0.001 to 0.1 mol of the seed compound are reacted.

(C) Examples of the catalyst include tertiary amines such as tripropylamine, tributylamine, N,
N'-dimethylpiperazine and the like. Also, the fourth
Examples of the quaternary ammonium salt include tetramethylammonium halide, tetraethylammonium halide, and tetrabutylammonium halide, and examples of the halide include chloride, bromide, and iodide. Examples of the quaternary ammonium base include tetramethylammonium hydroxide and benzyltrimethylammonium hydroxide. Examples of the tri-substituted phosphine include tripropyl phosphine, tributyl phosphine, triphenyl phosphine, tolyl phosphine, and the like. Examples of the quaternary phosphonium salt include tetramethylphosphonium halide, tetrabutylphosphonium halide, and methyltriphenyl. Examples thereof include phosphonium halide and ethyltriphenylphosphonium halide. Examples of the halide include chloride, bromide, and iodide. Among the compounds mentioned here, quaternary ammonium salts and quaternary phosphonium salts are preferred because the reaction proceeds less efficiently under milder conditions and the reaction proceeds efficiently. Particularly preferred are quaternary ammonium salts, among which tetramethylammonium halide, tetraethylammonium halide, and tetrabutylammonium halide are used. As a halide, a side reaction is further suppressed by using chloride or bromide, and the catalyst is removed after the reaction. Is also preferable because it can be easily removed by washing with water.

The reaction solution obtained as described above is mixed with an alkali metal hydroxide or an alkali metal alcoholate for 3 hours.
After adding about 6 mol and dehydrochlorinating, the alkali metal salt is separated by washing or filtration to obtain a reaction solution containing tris- (2,3-epoxypropyl) -isocyanurate. Examples of the alkali metal hydroxide include, for example, sodium hydroxide, potassium hydroxide, and lithium hydroxide. Examples of the alkali metal alcoholate include sodium methylate, sodium ethylate, potassium methylate, and potassium ethylate. . The tris- (2,3-epoxypropyl) -isocyanurate thus formed has β-tris- (2,3-epoxypropyl).
-Isocyanurate and α-type tris- (2,3-epoxypropyl) -isocyanurate in a weight ratio of 1: 3.

The tris- (2,3) thus obtained
The reaction solution containing (-epoxypropyl) -isocyanurate is adjusted to a concentration suitable for crystallization by concentration or dilution. The solid content can be measured by performing a treatment at 120 ° C. and 5 Torr or less for 3 hours with a rotary evaporator to dryness, and measuring the solid content weight to calculate the solid content.

In the step (B), the solid content of the reaction solution containing tris- (2,3-epoxypropyl) -isocyanurate is 10% by weight to 50% by weight, preferably 25% by weight.
It is adjusted to 40% by weight.

If the concentration is too low, the cooling temperature required for crystallization must be cooled to a low temperature, and a sufficient yield cannot be obtained.

Conversely, if the concentration is too high, the cooling temperature required for crystallization must be kept at a high temperature, and as a result, the filtration temperature must be kept at a high temperature.

The necessity of maintaining the cooling temperature range necessary for the crystallization is to selectively include the β-form rather than the α-form in the crystallized crystal.

Table 1 shows the tris- (2,3-epoxypropyl) -isocyanurate solid concentration (%) in the reaction solution.
And the temperature (° C.) at which a saturated solution is formed and the cooling temperature (° C.) required for crystallization. Here, the temperature at which a saturated solution is formed means that the reaction solution obtained in the step (B) is heated to 120 ° C.
Tris- (2,3-epoxypropyl) -isocyanurate obtained by drying at 2 Torr was pulverized to obtain a powder of 32 mesh or less, adjusted to epichlorohydrin and a predetermined solid concentration, and then stirred vigorously at room temperature. The temperature was further increased at a rate of 1 ° C./min to obtain the temperature at the time of complete dissolution.

[0026]

[Table 1] ―――――――――――――――――――――――――――――― Table 1 ―――――――――――――― ―――――――――――――――― Tris-(2,3-Epoxyfluoro)-isocyanurate solids concentration (%) 50 40 30 Temperature at which a saturated solution is formed (℃) 79 69 58 Cooling temperature required for crystallization (° C) 35 ± 5 25 ± 5 15 ± 5 ――――――――――――――――――――――――――――

[0027]

[Table 2] ―――――――――――――――――――――――――――――― Continued from Table 1 ―――――――――――― ―――――――――――――――――― Tris-(2,3-Ethoxyfluoro)-isocyanurate solids concentration (%) 25 15 10 Temperature at which a saturated solution is formed (℃) 53 39 29 Cooling temperature required for crystallization (° C) 11 ± 5 0 ± 5 −5 ± 5 ―――――――――――――――――――――――――――― In the step (C), a seed crystal is added to the liquid obtained in the step (B) at a temperature 5 to 20 ° C. lower than a temperature at which the liquid forms a saturated solution.

As the seed crystal, β-type or α-type tris- (2,3
-Epoxypropyl) -isocyanurate is used. When crystallization is performed without adding seed crystals, the supersaturation state continues even during cooling, and crystallization occurs at a stretch in the latter half of cooling. This is not preferable because it causes a decrease in purity due to incorporation of impurities such as epichlorohydrin and α-type tris- (2,3-epoxypropyl) -isocyanurate.

In the step (C), before the seed crystal is added, the reaction solution is heated to a temperature not lower than a temperature at which a saturated solution is formed, and tris- (2,3-epoxypropyl) -isocyanurate in the reaction solution is removed. After sufficient dissolution, the seed crystals can be added by slow cooling to a temperature 5-20 ° C. below the temperature at which the saturated solution is formed. This method is preferable in terms of filterability and the like, because the average particle size of the obtained crystals becomes uniform.

In the present invention, crystal growth starts with the added seed crystal as a nucleus.

If the step (C) is not heated above the temperature at which the saturated solution is formed but is maintained at a temperature 5 to 20 ° C. lower than the temperature at which the saturated solution is formed, at this temperature, the fine crystals Is generated, and this crystal together with a seed crystal added later also functions as a seed crystal, and it is difficult to control the number of seed crystals. Thus, once heated to a temperature above the temperature at which a saturated solution is formed, then 5-20 times above the temperature at which a saturated solution is formed.
It is preferable to cool to a temperature lower by 0 ° C. and add seed crystals.

After the seed crystal is added in step (C), stirring is preferably performed at the added temperature for 0.5 to 1 hour.

Thereafter, as step (D), slow cooling is performed. The cooling rate is within 20 ° C./hr, preferably 10 ° C./hr.
Within. Rapid cooling is not preferable because rapid crystal precipitation occurs and the purity decreases due to the incorporation of impurities.

In the above method for producing a β-type tris- (2,3-epoxypropyl) -isocyanurate crystal,
It is also possible to produce by a method without adding a seed crystal in the step (C), but in that case, it is necessary to slowly crystallize over a long time in the step (D). In that case, it is necessary to gradually cool at a cooling rate of, for example, 5 ° C./hr or less.

The crystallized β-form tris- (2,3-epoxypropyl) -isocyanurate crystals are separated by suction filtration, filter press method, centrifugal filtration method or the like.

In the step (E), the β-type tris- (2,3-epoxypropyl) -isocyanurate filtered off contains impurities, α-type tris- (2,3-epoxypropyl) -isocyanurate and epichlorohydrin. Since it is contained, it can be washed with various organic solvents. Examples of the organic solvent include methanol, ethanol, isopropyl alcohol, methyl ethyl ketone, acetonitrile, dimethylformamide, epichlorohydrin and the like.

The washing can be carried out at a temperature of 5 to 50 ° C., preferably 5 to 30 ° C. High temperature, for example, 30-50 ° C
Increases the solubility and saves solvent usage,
Operation at a temperature close to the flash point or boiling point. A centrifugal filter may cause an accident due to ignition of static electricity.
(2,3-epoxypropyl) -isocyanurate is
The ventilation of the pressurized gas may cause re-precipitation in the filter medium or cake, which may reduce the filterability. In addition, α-tris- (2,3-epoxypropyl)-
There are restrictions such as the necessity of a heat retaining facility for preventing isocyanurate from reprecipitating. Above 50 ° C., a special thermal filtration system is required. If the temperature is lower than 5 ° C., a large amount of solvent is required.

Β-tris obtained through the step (E)
The (2,3-epoxypropyl) -isocyanurate crystal has an average particle diameter of 10 to 500 μm. Among these particle diameters, the invention of the present application has an average particle diameter exceeding 20 μm and exceeding 5 μm.
Those having a range of not more than 00 μm can be used.

The thus obtained β-form tris- (2,3-epoxypropyl) -isocyanurate crystal obtained in the step (E) is subjected to a gas flow at normal pressure or reduced pressure for 100 to 14 hours.
By drying at 0 ° C., preferably at a temperature of 120 to 140 ° C., residual epichlorohydrin is reduced to 1000 ppm.
Hereafter, it can be particularly preferably reduced to 300 ppm or less. The above-mentioned 100-140 degreeC, Preferably it is 120-
The temperature of 140 ° C. is a temperature not lower than the melting point of α-form tris- (2,3-epoxypropyl) -isocyanurate,
And a temperature equal to or lower than the melting point of β-type tris- (2,3-epoxypropyl) -isocyanurate. By drying in an air stream at this temperature, β-form tris- (2,3-epoxypropyl) -isocyanurate crystal containing α-form tris- (2,3-epoxypropyl) -isocyanurate in the crystal body In the above, a portion of α-type tris- (2,3-epoxypropyl) -isocyanurate is melted and liquefied. Through this liquid portion, the epichlorohydrin impurity is discharged from the crystal to the outside of the crystal.

However, in the present invention, the β-form tris- (2,3-epoxypropyl) -isocyanurate crystal obtained in the step (E) is heated to 100 to 140 ° C., preferably 12 to 140 ° C.
The organic solvent remaining in the crystal can be reduced only by performing the pulverizing step in a stream without passing through the drying step at 0 to 140 ° C.

The pulverization is performed by pulverizing the β-type tris- (2,3-epoxypropyl) -isocyanurate crystal to an average particle diameter of 0.5 to 20 μm. This pulverization can reduce the residual organic solvent to 300 ppm or less.

The average particle size and the particle size distribution of the pulverized product are controlled by the pulverizing conditions and the classifying rotor.
When the (2,3-epoxypropyl) -isocyanurate crystal is pulverized to an average particle diameter of 0.5 to 20 μm, the organic solvent inside the crystal can be efficiently removed. The smaller the average particle size of the pulverized crystals, the higher the solvent removal rate. However, if the average particle size is too small, the pulverization efficiency will decrease. When the average particle size is 20 μm or more, the solvent removal rate is low.

<Method for Quantifying Epichlorohydrin Remaining in Crystal> Epichlorohydrin remaining in the crystal is dissolved by adding a 20-fold amount of dimethylformamide to the sample (crystal) and heating at 80 ° C. Can be quantified by gas chromatography.

[0044]

EXAMPLES (Example of Production of β-Form Tris- (2,3-epoxypropyl) -isocyanurate Crystalline) (A) Step: A stirrer, a thermometer, a continuous dropping device, and epichlorohydrin and water were mixed under reduced pressure. To a flask equipped with a device for concentrating boiling steam and returning only epichlorohydrin to the reaction system, 774 g (6 mol) of cyanuric acid, 8328 g (90 mol) of epichlorohydrin, and 213 g of a 15.5% by weight aqueous solution of tetramethylammonium chloride were added, and 89 The reaction was carried out by refluxing while stirring at ~ 120 ° C for 5 hours. Next, the temperature of the reaction system was cooled to 50 ° C., and 1536 g of a 50% by weight aqueous sodium hydroxide solution was stirred at 50 ° C. for 6 hours under reduced pressure of 100 to 60 Torr while stirring to remove hydrochloric acid. Thereafter, the resulting sodium chloride was washed by adding and dissolving 3600 g of water, and then separated, and further washed by adding 1200 g of a 5% by weight aqueous solution of sodium dihydrogen phosphate.
Neutralize the excess sodium hydroxide used, then
Washed with 00 g of water. Step (B): A part of epichlorohydrin was distilled off at 70 ° C. under reduced pressure until the solid concentration in the reaction solution became 40% by weight, to obtain 4000 g of a control solution. Step (C): cooling to 60 ° C., β-tris-
(2,3-epoxypropyl) -isocyanurate in 1
After adding 1.2 g, (D) step: cooling to 25 ° C. in 4 hours, and adding β-type tris-
(2,3-Epoxypropyl) -isocyanurate crystals were precipitated and separated by filtration. . Step (E): The obtained crystal was washed with 1200 g of methanol and filtered. The cake obtained is 5
After drying under reduced pressure of Torr for 4 hours, β-form tris- (2,3-epoxypropyl) -isocyanurate crystal was obtained in a yield of 280 g. The obtained crystal had a residual epichlorohydrin content of 700 ppm and an epoxy equivalent of 101.
g / eq. The melting point was 148 to 158 ° C., and white crystals having an average particle size of 75 μm were obtained.

Example 1 The β-form tris- (2,3-epoxypropyl) -isocyanurate crystal obtained in the production example was prepared by ALPINE 20
It was pulverized with a 0AFG type counter jet mill. Grinding was performed under a nitrogen pressure of 6.0 kg / cm ² and a nitrogen amount of 400 Nm ³ /
h, sample supply rate 40 kg / h, classification rotor 50
The test was performed at 00 rpm. Average particle size 75 by pulverization and classification
μm crystals are finely pulverized to an average particle size of 3.0 μm, and the remaining epichlorohydrin is reduced from 700 ppm to 180 p.
pm.

Example 2 The β-form tris- (2,3-epoxypropyl) -isocyanurate crystal obtained in the production example was prepared by ALPINE 20
It was pulverized with a 0AFG type counter jet mill. Grinding was performed under a nitrogen pressure of 6.0 kg / cm ² and a nitrogen amount of 800 Nm ³ /
h, the sample was supplied at a rate of 30 kg / h, and the mixture was pulverized at a classifying rotor of 12000 rpm. The crystals having an average particle size of 75 μm were finely pulverized to an average particle size of 1.5 μm by pulverization, and the remaining epichlorohydrin was reduced to 90 ppm.

Reference Example 1 The crystals obtained in the Production Example were further dried at 120 ° C. under a reduced pressure of 5 Torr for 4 hours. The residual epichlorohydrin was 200 ppm.

[0048]

According to the present invention, tris- (2,3-epoxypropyl) -isocyanurate crystal particles are formed by evaporating volatile components from the particle surface with an average particle size of 0.5 to 20 μm.
The remaining organic solvent in the tris- (2,3-epoxypropyl) -isocyanurate crystal by grinding to the maximum can be removed.

The tris- (2,2) obtained by the conventional recrystallization method
In the 3-epoxypropyl) -isocyanurate crystal, the residual organic solvent taken into the crystal is removed by heating the organic solvent to a temperature higher than the melting point of tris- (2,3-epoxypropyl) -isocyanurate. Had been removed. The β-type tris- (2,3-epoxypropyl) -isocyanurate crystals required heating at a high temperature of 150 ° C. or higher.

From the reaction solution containing tris- (2,3-epoxypropyl) -isocyanurate, β-type tris- (2,3-α-type containing tris- (2,3-epoxypropyl) -isocyanurate is used. 3-epoxypropyl) -isocyanurate crystals are also used for the precipitation.
Heating to a temperature of from 00 to 140 ° C., preferably from 120 to 140 ° C. to melt the α-form tris- (2,3-epoxypropyl) -isocyanurate in the crystal to form a molten portion formed in the crystal Although it is possible to remove the organic solvent (epichlorohydrin) through the solvent, in the present invention, it is possible to remove the organic solvent only by pulverizing the tris- (2,3-epoxypropyl) -isocyanurate crystal in an air stream. did it. In particular, it is effective for removing the residual organic solvent from the β-type tris- (2,3-epoxypropyl) -isocyanurate crystal.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Motohiko Hidaka 722-1, Tsuboi-cho, Funabashi-shi, Chiba Nissan Chemical Industry Co., Ltd. Central Research Laboratory (72) Inventor Atsumi Aoki 6901-1, Onoda, Onoda-shi, Yamaguchi Nissan Chemical F-term in the Onoda Factory of Industrial Co., Ltd. (reference) 4C063 AA05 BB03 CC71 DD43 EE10

Claims (7)

[Claims] 1. Tris- (2,3-epoxypropyl)
-Tris- (2,3- by grinding isocyanurate crystal particles from the particle surface while evaporating volatile components
(Epoxypropyl) -Isocyanurate Crystalline. 2. The method for reducing residual organic solvent according to claim 1, wherein the pulverization in which volatile components evaporate from the particle surface is pulverization performed in an air stream. 3. The method of claim 1, wherein the crystalline particles have an average particle size of 0.5 to 20 μm.
The method for reducing residual organic solvent according to claim 1 or 2, wherein the organic solvent is pulverized to m. 4. The method for reducing a residual organic solvent according to claim 1, wherein the concentration of the residual organic solvent is 300 ppm or less. 5. Tris- (2,3-epoxypropyl)
-Isocyanurate crystal particles are β-tris- (2,
The method for reducing a residual organic solvent according to any one of claims 1 to 4, which is a crystalline particle of (3-epoxypropyl) -isocyanurate. 6. A chlorohydrin ester of isocyanuric acid obtained by reacting cyanuric acid and epichlorohydrin in the presence of a β-form tris- (2,3-epoxypropyl) -isocyanurate crystal in the presence of a catalyst, An alkali metal chloride produced by dehydrochlorination with an alkali is separated and crystallized from the obtained reaction solution containing tris- (2,3-epoxypropyl) -isocyanurate. 5. The method for reducing residual organic solvent according to the above. 7. The method for reducing residual organic solvent according to claim 5, wherein the residual organic solvent is epichlorohydrin.